AP BIOLOGY

Detailed explanation-1: -Fermentation enables glycolysis to continue supplying a cell with ATP in anaerobic conditions.

Detailed explanation-2: -Glycolysis occurs in both aerobic and anaerobic states. In aerobic conditions, pyruvate enters the citric acid cycle and undergoes oxidative phosphorylation leading to the net production of 32 ATP molecules. In anaerobic conditions, pyruvate converts to lactate through anaerobic glycolysis.

Detailed explanation-3: -During the absence of oxygen (anaerobic conditions) and in the cells lacking mitochondria, anaerobic glycolysis prevails. The pyruvate is reduced to lactate as NADH is reoxidized to NAD+ by lactate dehydrogenase. This process is an important source of ATP for cells that lack mitochondria such as erythrocytes.

Detailed explanation-4: -In certain bacteria and animal muscle cells, under anaerobic conditions, the pyruvic acid is reduced to lactic acid by lactate dehydrogenase. This is called lactic acid fermentation.